The Massachusetts Water Resources Authority
has been granted a federal National Pollutant Discharge Elimination
System (NPDES) permit to discharge effluent from the Deer Island
Wastewater Treatment Plant into Massachusetts Bay. MWRA is required by the permit to post
environmental reports and related information online.

MWRA developed this plan to ensure that discharge from the
outfall does not result in adverse impacts to the Bay. The
Plan identifies thresholds that can suggest that effluent
quality or conditions in the Bay may be changing. "Caution" or
"Warning" level exceedances of Contingency Plan
thresholds for water quality monitoring in Massachusetts Bay.
Designed to detect potential effects of the outfall.

The Massachusetts Department of Environmental Protection (DEP) requires MWRA
to post online notifications when discharges of treated combined sewage occur at the Cottage Farm CSO Treatment Facility in the Charles River. This is part of MWRA's CSO Variance.

MWRA is limited by its NPDES discharge permit to an average dry day flow of 436 million gallons per day. Each year, MWRA must submit a report assessing the effectiveness of demand management programs and water conservation efforts that are being pursued with communities in the service area.

Groundwater Remediation

MWRA
prohibits discharges into the MWRA system for groundwater
remediation activities. Any proposed changes to this rule must be posted online. There are currently no proposed changes.

MWRA regulates discharges from certain business or industrial sewer users and prescribes standards and limits for both the quantity and quality of substances that may be discharged. The permit requires MWRA to develop and enforce these limits to prevent pollutants from being introduced into the system that could interfere with the operation or performance of the works, or cause problems with NPDES permit compliance or sludge disposal practices.

MWRA submitted to regulators a pollution prevention plan that addresses households and industries discharging in MWRA's sewer service area. The plan includes steps for identifying and controlling sources of PCBs, and for containing chemical spills.

MWRA also publishes the Industrial Waste Report which documents ongoing efforts to implement the requirements of 40 CFR Part 403, General Pretreatment Regulations. A Healthy Environment Starts at Home is a guide to hazardous household substances, and their effects on wastewater and receiving water.

Prior
Notice

MWRA must provide at least a 30-day written prior notice to the public, EPA and DEP, the National Marine Fisheries Service and OMSAP/advisory committees of any significant change in the volume or character of pollutants being introduced into the treatment plant that may cause the discharge to lead to an exceedance of water quality standards in the receiving water.